In general, as one operating principle of a touch screen, infrared rays are radiated using an infrared illumination, and irradiated infrared rays are irradiated to a rear surface of a screen. When a user touches a front surface of the screen with his/her hand, a part of the touched hand reflects the infrared rays.
A camera installed in a system senses such infrared rays reflected by the touched hand, and an image processing system calculates a touch point by sensing an image.
When the hand touches the screen by using the system, the reflected infrared rays become nonuniform, and a reflection area may be changed depending on a reflection dimension of the hand and proximity.
Accordingly, even though a finger point is generally recognized as a touch point, a finger knuckle is also recognized as the touch point for various reasons, and as a result, a touch screen system does not accurately recognize the actual touch point.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.